DBA: Linux

Convert a Single Instance Database to Oracle RAC 10g on RHEL3

by Vincent Chan

Learn how to convert a single-instance database to Oracle Real Application Clusters (RAC) 10g on Red Hat Enterprise Linux 3 (RHEL3), step by step.

Contents
Overview
Step 1: Preliminary Installation
Step 2: Migrate Your Database to ASM
Step 3: Install Cluster Ready Services (CRS) Software
Step 4: Install Oracle RAC Software
Step 5: Post Installation
Step 6: Test Transparent Application Failover (TAF)
Conclusion

Download for this article:
 Oracle Database 10g Enterprise Edition and Clusterware for Linux x86
 Oracle ASMlib Drivers

For those with limited hands-on experience, implementing Oracle RAC 10g can be an intimidating prospect. But it doesn't have to be that way.

In this guide, I'll provide the precise procedures for converting a single-instance Oracle 10g database to Oracle RAC on RHEL3. We'll use Oracle Automatic Storage Management (ASM), an integrated file system and a volume management solution built into the Oracle database kernel, for RAC database storage because it simplifies database storage management tasks while offering storage reliability and performance.

To summarize on a very high level, there are several ways to convert your database to RAC. If the database is small, you can consider installing a new RAC database on ASM and export/import your data from your current database to the RAC database. For a larger database, the preferred method would be to use RMAN to migrate the database files over to ASM. The method demonstrated here is a two-phase approach: first, migrating the data to ASM, and second, converting the single-instance database to RAC. If you are new to ASM, I would recommend taking this migration path to get familiar with ASM before leaping into ASM and RAC at the same time. (For more information about Oracle ASM, visit the Oracle ASM Product Center or refer to the documentation.)

This guide requires a basic understanding of RAC architecture and some familiarity with managing and administering Oracle Database and Red Hat Enterprise Linux. Refer to the documentation for details.


Overview

The RAC cluster comprises two Intel x86 servers running on RHEL3 (Kernel 2.4.21-27). Each node has access to a shared storage and connectivity to the public and private network.

This guide is structured into the following steps:

  1. Preliminary Installation
  2. Migrating Your Database to ASM
  3. Installing Oracle Cluster Ready Services (CRS) Software
  4. Installing Oracle RAC Software
  5. Post Installation
  6. Testing Transparent Application Failover (TAF)
Unless otherwise specified, you should execute all steps on both nodes.

Here's an overview of our single-instance database environment before converting to RAC:

Host Name
Instance Name
Database Name
$ORACLE_BASE
Database File Storage
salmon1 prod1 prod1 /u01/app/oracle ext3

And an overview of the RAC database environment:

Host Name
Instance Name
Database Name
$ORACLE_BASE
Database File Storage
OCR & CRS Voting Disk
salmon1 prod1a prod1 /u01/app/oracle ASM Raw
salmon2 prod1b prod1 /u01/app/oracle ASM Raw

You'll install the Oracle Home on each node for redundancy.The ASM and RAC instances share the same Oracle Home on each node.

Step 1: Preliminary Installation

1a. Verify software package versions.

Install the required packages. Additional information can be obtained from the documentation.

[root@salmon1]# rpm -qa | grep -i compat
compat-libstdc++-7.3-2.96.128
compat-gcc-c++-7.3-2.96.128
compat-libstdc++-devel-7.3-2.96.128
compat-db-4.0.14-5
compat-glibc-7.x-2.2.4.32.6
compat-slang-1.4.5-5
compat-gcc-7.3-2.96.128
compat-pwdb-0.62-3
[root@salmon1]# 
[root@salmon1]# rpm -qa | grep openmotif
openmotif-2.2.3-3.RHEL3
[root@salmon1]# 
[root@salmon1]# rpm -qa | grep -i gcc
gcc-gnat-3.2.3-42
gcc-c++-ssa-3.5ssa-0.20030801.48
compat-gcc-c++-7.3-2.96.128
libgcc-ssa-3.5ssa-0.20030801.48
gcc-3.2.3-42
gcc-g77-3.2.3-42
gcc-java-3.2.3-42
gcc-ssa-3.5ssa-0.20030801.48
gcc-g77-ssa-3.5ssa-0.20030801.48
gcc-objc-ssa-3.5ssa-0.20030801.48
libgcc-3.2.3-42
gcc-c++-3.2.3-42
gcc-objc-3.2.3-42
gcc-java-ssa-3.5ssa-0.20030801.48
compat-gcc-7.3-2.96.128

1b. Verify kernel parameters.

Verify the following kernel parameters. Additional information can be obtained from the documentation.

[root@salmon1]# sysctl -a | grep shm
kernel.shmmni = 4096
kernel.shmall = 2097152
kernel.shmmax = 2147483648
[root@salmon1]# sysctl -a | grep sem
kernel.sem = 250        32000   100     128
[root@salmon1]# sysctl -a | grep -i ip_local
net.ipv4.ip_local_port_range = 1024     65000
[root@salmon1]# sysctl -a | grep -i file-max
fs.file-max = 65536
1c. Create the Oracle Base directory, oracle user, and groups.

Using the information below on node 1, create the oracle user and the oinstall and dba groups on the second node.

[oracle@salmon1]$ hostname
salmon1.dbsconsult.com
[oracle@salmon1]$ 
[oracle@salmon1]$ id
uid=500(oracle) gid=500(dba) groups=500(dba),501(oinstall)
[oracle@salmon1]$ 
[oracle@salmon1]$ echo $ORACLE_BASE
/u01/app/oracle 
1d. Edit the oracle user environment file.
[oracle@salmon1]$ more .bash_profile
# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

export PATH=$PATH:$HOME/bin
export ORACLE_SID=prod1
export ORACLE_BASE=/u01/app/oracle
export ORACLE_HOME=$ORACLE_BASE/product/10.1.0
export LD_LIBRARY_PATH=$ORACLE_HOME/lib
export PATH=$ORACLE_HOME/bin:$PATH
umask 022
1e. Configure the oracle user shell limits.
[root@salmon1]# more /etc/security/limits.conf
*                soft    nproc           2047
*                hard   nproc           16384
*                soft    nofile           1024
*                hard   nofile           65536
[root@salmon1]# grep pam_limits /etc/pam.d/login
session    required     /lib/security/pam_limits.so                              
1f. Configure public and private network.

Using the information below, make the necessary changes to network interface devices eth0 (public) and eth1 (private).

[root@salmon1]# redhat-config-network
Host Name
IP Address
Type
salmon1.dbsconsult.com 192.168.0.184 Public (eth0)
salmon2.dbsconsult.com 192.168.0.185 Public (eth0)
salmon1.dbsconsult.com 10.10.10.84 Private (eth1)
salmon2.dbsconsult.com 10.10.10.85 Private (eth1)
salmon1-vip.dbsconsult.com 192.168.0.186 Virtual
salmon2-vip.dbsconsult.com 192.168.0.187 Virtual

1g. Edit the /etc/hosts file.

127.0.0.1       localhost.localdomain            localhost
10.10.10.84     sallocal1.dbsconsult.com         sallocal1
10.10.10.85     sallocal2.dbsconsult.com         sallocal2
192.168.0.184   salmon1.dbsconsult.com           salmon1
192.168.0.185   salmon2.dbsconsult.com           salmon2
192.168.0.186   salmon1-vip.dbsconsult.com       salmon1-vip
192.168.0.187   salmon2-vip.dbsconsult.com       salmon2-vip
Verify the hostname and the configured network interface devices.
[root@salmon1]# hostname
salmon1.dbsconsult.com
[root@salmon1]# /sbin/ifconfig

1h. Establish user equivalence with SSH.

During the Cluster Ready Services (CRS) and RAC installation, the Oracle Universal Installer (OUI) has to be able to copy the software as oracle to all RAC nodes without being prompted for a password. In Oracle 10g, this can be accomplished using ssh instead of rsh.

To establish user equivalence, generate the user's public and private keys as the oracle user on both nodes.

[oracle@salmon1]$ ssh-keygen -t dsa
Generating public/private dsa key pair.
Enter file in which to save the key (/home/oracle/.ssh/id_dsa):
Created directory '/home/oracle/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/oracle/.ssh/id_dsa.
Your public key has been saved in /home/oracle/.ssh/id_dsa.pub.
The key fingerprint is:
5d:8c:42:97:eb:42:ae:52:52:e9:59:20:2a:d3:6f:59 oracle@salmon1.dbsconsult.com
Test the connection on every node. Verify that you are not prompted for password when you run the following the second time.
ssh salmon1 date
ssh salmon2 date 
ssh sallocal1 date
ssh sallocal2 date
ssh salmon1.dbsconsult.com date
ssh salmon2.dbsconsult.com date
ssh sallocal1.dbsconsult.com date
ssh sallocal2.dbsconsult.com date
1i. Configure hangcheck timer kernel module.

The hangcheck timer kernel module monitors the system's health and restarts a failing RAC node. It uses two parameters, hangcheck_tick (defines the system checks frequency) and hangcheck_margin (defines the maximum hang delay before a RAC node is reset), to determine if a node is failing.

Add the following line in /etc/rc.d/rc.local to load the hangcheck module automatically.

[root@salmon1]# grep insmod /etc/rc.d/rc.local 
insmod hangcheck-timer hangcheck_tick=30 hangcheck_margin=180
1j. Recreate database control file.

Make sure that the entries below are sized appropriately in the control file before converting to RAC. If required, recreate the database control file with the right settings.

MAXLOGFILES 
MAXLOGMEMBERS 
MAXDATAFILES 
MAXINSTANCES 
MAXLOGHISTORY 
1k. Resize the database buffer cache.

When transitioning from a single instance database to RAC, additional memory is required for the database buffer cache. In RAC, space is allocated for the Global Cache Service (GCS) in every block buffer cache. The amount of additional memory requires depends on how the application accesses the data—that is, if the same block is cached in more than one instance.

I observed an increase of about 8% buffer cache usage during an experimental demonstration. Use the buffer cache advisory to determine an optimal buffer cache size or let Oracle take control by switching to Oracle Automatic Shared Memory Management (ASMM).


Step 2: Migrate Your Database to ASM

The Oracle Cluster Synchronization Services (CSS) daemon is required for synchronization between the ASM instance and the database instances. The CSS daemon must be up before the ASM instance can be started. When you installed or upgraded to Oracle Database 10g, the CSS should have already been configured for the single-node version and it should start automatically when the system reboots.

 
[root@salmon1]# ps –ef | grep ocssd.bin | wc –l 
      17
2a. Download ASM RPMs.

Download the following ASM RPMs from OTN:

  • oracleasm-support-2.0.0-1.i386.rpm
  • oracleasm-2.4.21-27.EL-1.0.4-2.i686.rpm (driver for UP kernel) or oracleasm-2.4.21-27.ELsmp-1.0.4-1.i686.rpm (driver for SMP kernel)
  • oracleasmlib-2.0.0-1.i386.rpm

2b. Install the ASM RPMs.

Install the ASM RPMs as the root user.

[root@salmon1]# rpm -i oracleasm-support-2.0.0-1.i386.rpm
[root@salmon1]# rpm -i oracleasm-2.4.21-27.EL-1.0.4-2.i686.rpm
Linking module oracleasm.o into the module path [  OK  ]
[root@salmon1]# rpm -i oracleasmlib-2.0.0-1.i386.rpm
[root@salmon1]# rpm -qa | grep oracleasm
oracleasm-2.4.21-27.EL-1.0.4-2
oracleasm-support-2.0.0-1
oracleasmlib-2.0.0-1
2c. Configure ASM.

Configure the ASMLib as the root user.

[root@salmon1]# /etc/init.d/oracleasm configure
Configuring the Oracle ASM library driver.

This will configure the on-boot properties of the Oracle ASM library
driver.  The following questions will determine whether the driver is
loaded on boot and what permissions it will have.  The current values
will be shown in brackets ('[]').  Hitting <enter> without typing an
answer will keep that current value.  Ctrl-C will abort.

Default user to own the driver interface []: oracle
Default group to own the driver interface []: dba
Start Oracle ASM library driver on boot (y/n) [n]: y
Fix permissions of Oracle ASM disks on boot (y/n) [y]: y
Writing Oracle ASM library driver configuration            [  OK  ]
Creating /dev/oracleasm mount point                        [  OK  ]
Loading module "oracleasm"                                 [  OK  ]
Mounting ASMlib driver filesystem                          [  OK  ]
Scanning system for ASM disks    
2d. Create ASM disks.

Create the ASM disks on any one node as the root user.

[root@salmon1]# /etc/init.d/oracleasm createdisk VOL1 /dev/sdg5
Marking disk "/dev/sdg5" as an ASM disk                      [  OK  ]
[root@salmon1]# /etc/init.d/oracleasm createdisk VOL2 /dev/sdg6
Marking disk "/dev/sdg6" as an ASM disk                      [  OK  ]
[root@salmon1]# /etc/init.d/oracleasm createdisk VOL3 /dev/sdg7
Marking disk "/dev/sdg7" as an ASM disk                      [  OK  ]
[root@salmon1]# /etc/init.d/oracleasm createdisk VOL4 /dev/sdg8
Marking disk "/dev/sdg8" as an ASM disk                      [  OK  ]
[root@salmon1]# /etc/init.d/oracleasm createdisk VOL5/dev/sdg9
Marking disk "/dev/sdg9" as an ASM disk                      [  OK  ]
[root@salmon1]# /etc/init.d/oracleasm createdisk VOL6 /dev/sdg10
Marking disk "/dev/sdg10" as an ASM disk                    [  OK  ]
[root@salmon1]# /etc/init.d/oracleasm createdisk VOL7 /dev/sdg11
Marking disk "/dev/sdg11" as an ASM disk                    [  OK  ]
[root@salmon1]# /etc/init.d/oracleasm createdisk VOL8 /dev/sdg12
Marking disk "/dev/sdg12" as an ASM disk                    [  OK  ]
[root@salmon1]# /etc/init.d/oracleasm createdisk VOL9 /dev/sdg13
Marking disk "/dev/sdg13" as an ASM disk                    [  OK  ]
[root@salmon1]# /etc/init.d/oracleasm createdisk VOL10 /dev/sdg14
Marking disk "/dev/sdg14" as an ASM disk                    [  OK  ]
Verify that the ASM disks are visible from every node.
[root@salmon1]# /etc/init.d/oracleasm listdisks
VOL1
VOL2
VOL3
VOL4
VOL5
VOL6
VOL7
VOL8
VOL9
VOL10
[root@salmon1]# /etc/init.d/oracleasm scandisks
Scanning system for ASM disks                              [  OK  ]
2e. Create ASM init.ora.

On the first node, create an init+ASM1A.ora file in $ORACLE_HOME/dbs with the following parameters:

#asm_diskgroups='DG1', ‘DG2’, ‘RECOVERYDEST’
asm_diskstring='ORCL:VOL*'
background_dump_dest=/u01/app/oracle/admin/+ASM/bdump
core_dump_dest=/u01/app/oracle/admin/+ASM/cdump
user_dump_dest=/u01/app/oracle/admin/+ASM/udump
instance_type=asm
large_pool_size=16M
remote_login_passwordfile=exclusive
+ASM1A.instance_number=1
+ASM1B.instance_number=2
2f. Create ASM password file.

Using the orapwd utility, create an orapw+ASM1A file in $ORACLE_HOME/dbs on the first node.

[oracle@salmon1]$ cd $ORACLE_HOME/dbs
[oracle@salmon1]$ orapwd file=orapw+ASM1A password=sys entries=5
2g. Create the first ASM instance.

Create the first ASM instance on the first node. The second ASM instance will be created in Post Installation after the CRS software is installed on the second node.

[oracle@salmon1]$ export ORACLE_SID=+ASM1A
[oracle@salmon1]$ sqlplus / as sysdba

SQL*Plus: Release 10.1.0.3.0 - Production on Thu May 26 05:51:07 2005
 
Copyright (c) 1982, 2004, Oracle.  All rights reserved.
 
Connected to an idle instance.
 
SQL> startup
ORACLE instance started.
 
Total System Global Area  104857600 bytes
Fixed Size                777616 bytes
Variable Size             104079964 bytes
Database Buffers          0 bytes
Redo Buffers              0 bytes
ORA-15110: no diskgroups mounted
2h. Create the ASM instance spfile.

Create a spfile immediately after the ASM instance starts. With spfile, any newly created disk groups are automatically added to the spfile.

SQL> create spfile from pfile;

File created.
2i. Create disk groups.

Create three disk groups: DG1, DG2, and RECOVERYDEST. DG1 and DG2 will be used to store Oracle data files and redo logs. RECOVERYDEST will be used as the flash recovery area.

SQL> create diskgroup dg1 normal redundancy
  2  failgroup fg1a disk
  3  'ORCL:VOL1','ORCL:VOL2'
  4  failgroup fg1b disk
  5  'ORCL:VOL3','ORCL:VOL4';
 
Diskgroup created.

SQL> create diskgroup dg2 normal redundancy
  2  failgroup fg2a disk
  3  'ORCL:VOL5','ORCL:VOL6'
  4  failgroup fg2b disk
  5  'ORCL:VOL7','ORCL:VOL8';
 
Diskgroup created.
 
SQL> create diskgroup recoverydest normal redundancy
  2  failgroup fgrd1 disk
  3  'ORCL:VOL9'
  4  failgroup fgrd2 disk
  5  'ORCL:VOL10';
 
Diskgroup created.

SQL> show parameter diskgroup
 
NAME                           TYPE           VALUE
------------------------------ -----------    -----------------------------
asm_diskgroups                 string         DG1, DG2, RECOVERYDEST

SQL>  select name,total_mb from v$asm_diskgroup;
 
NAME                           TOTAL_MB
-------------------------      -------------------
DG1                            36864
DG2                            36864
RECOVERYDEST                   73728
 
3 rows selected.

SQL>  select name,path,failgroup from v$asm_disk;
 
NAME         PATH               FAILGROUP
--------     ---------------    ----------------
VOL1         ORCL:VOL1          FG1A
VOL10        ORCL:VOL10         FGRD2
VOL2         ORCL:VOL2          FG1A
VOL3         ORCL:VOL3          FG1B
VOL4         ORCL:VOL4          FG1B
VOL5         ORCL:VOL5          FG2A
VOL6         ORCL:VOL6          FG2A
VOL7         ORCL:VOL7          FG2B
VOL8         ORCL:VOL8          FG2B
VOL9         ORCL:VOL9          FGRD1
 
10 rows selected.
2j. Configure flash recovery area.
   
SQL> connect sys/sys@prod1 as sysdba
Connected.
SQL> alter database disable block change tracking;

Database altered.

SQL> alter system set db_recovery_file_dest_size=72G;

System altered.

SQL> alter system set db_recovery_file_dest=’+RECOVERYDEST’;

System altered.
2k. Migrate data files to ASM.

You must use RMAN to migrate the data files to ASM disk groups. All data files will be migrated to the newly created disk group, DG1. The redo logs and control files are created in DG1 and DG2. In a production environment, you should store redo logs on different set of disks and disk controllers from the rest of the Oracle data files.

                                 
SQL> connect sys/sys@prod1 as sysdba
Connected.
SQL> alter system set db_create_file_dest=’+DG1’;

System altered. 

SQL> alter system set control_files='+DG1/cf1.dbf' scope=spfile;

System altered.

SQL> shutdown immediate;

[oracle@salmon1]$ rman target /

RMAN> startup nomount;
 
Oracle instance started
 
Total System Global Area      419430400 bytes
Fixed Size                    779416 bytes
Variable Size                 128981864 bytes
Database Buffers              289406976 bytes
Redo Buffers                  262144 bytes
 
RMAN> restore controlfile from '/u02/oradata/prod1/control01.ctl';
 
Starting restore at 26-MAY-05
using target database controlfile instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=160 devtype=DISK
 
channel ORA_DISK_1: copied controlfile copy
output filename=+DG1/cf1.dbf
Finished restore at 26-MAY-05

RMAN> alter database mount;
 
database mounted
released channel: ORA_DISK_1
 
RMAN> backup as copy database format '+DG1';

Starting backup at 26-MAY-05
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=160 devtype=DISK
channel ORA_DISK_1: starting datafile copy
input datafile fno=00001 name=/u02/oradata/prod1/system01.dbf
output filename=+DG1/prod1/datafile/system.257.1 tag=TAG20050526T073442 recid=1 stamp=559294642
channel ORA_DISK_1: datafile copy complete, elapsed time: 00:02:49
channel ORA_DISK_1: starting datafile copy
input datafile fno=00003 name=/u02/oradata/prod1/sysaux01.dbf
output filename=+DG1/prod1/datafile/sysaux.258.1 tag=TAG20050526T073442 recid=2 stamp=559294735
channel ORA_DISK_1: datafile copy complete, elapsed time: 00:01:26
channel ORA_DISK_1: starting datafile copy
input datafile fno=00002 name=/u02/oradata/prod1/undotbs01.dbf
output filename=+DG1/prod1/datafile/undotbs1.259.1 tag=TAG20050526T073442 recid=3 stamp=559294750
channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:15
channel ORA_DISK_1: starting datafile copy
input datafile fno=00004 name=/u02/oradata/prod1/users01.dbf
output filename=+DG1/prod1/datafile/users.260.1 tag=TAG20050526T073442 recid=4 stamp=559294758
channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:07
channel ORA_DISK_1: starting datafile copy
copying current controlfile
output filename=+DG1/prod1/controlfile/backup.261.1 tag=TAG20050526T073442 recid=5 stamp=559294767
channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:08
Finished backup at 26-MAY-05

RMAN> switch database to copy;
 
datafile 1 switched to datafile copy "+DG1/prod1/datafile/system.257.1"
datafile 2 switched to datafile copy "+DG1/prod1/datafile/undotbs1.259.1"
datafile 3 switched to datafile copy "+DG1/prod1/datafile/sysaux.258.1"
datafile 4 switched to datafile copy "+DG1/prod1/datafile/users.260.1"

RMAN> alter database open;
 
database opened

RMAN> exit

SQL> connect sys/sys@prod1 as sysdba
Connected.
SQL> select tablespace_name, file_name from dba_data_files;
 
TABLESPACE               FILE_NAME                                          
---------------------    -----------------------------------------
USERS                    +DG1/prod1/datafile/users.260.1                             
SYSAUX                   +DG1/prod1/datafile/sysaux.258.1                          
UNDOTBS1                 +DG1/prod1/datafile/undotbs1.259.1                         
SYSTEM                   +DG1/prod1/datafile/system.257.1                          

                              
2l. Migrate temp tablespace to ASM.
SQL> alter tablespace temp add tempfile size 100M;
 
Tablespace altered.

SQL> select file_name from dba_temp_files;
 
FILE_NAME              
-------------------------------------                            
+DG1/prod1/tempfile/temp.264.3         
2m. Migrate redo logs to ASM.

Drop existing redo logs and recreate them in ASM disk groups, DG1 and DG2.

SQL> alter system set db_create_online_log_dest_1='+DG1';
 
System altered.
 
SQL> alter system set db_create_online_log_dest_2='+DG2';
 
System altered.

SQL> select group#, member from v$logfile;
 
         GROUP#     MEMBER
---------------     ----------------------------------
             1      /u03/oradata/prod1/redo01.log
             2      /u03/oradata/prod1/redo02.log

SQL> alter database add logfile group 3 size 10M;

Database altered. 

SQL> alter system switch logfile;

System altered.

SQL> alter database drop logfile group 1; 

Database altered. 

SQL> alter database add logfile group 1 size 100M;

Database altered. 

SQL> alter database drop logfile group 2; 

Database altered. 

SQL> alter database add logfile group 2 size 100M;

Database altered. 

SQL> alter system switch logfile;

System altered.

SQL> alter database drop logfile group 3; 

Database altered.

SQL> select group#, member from v$logfile;
 
         GROUP#     MEMBER
---------------     ----------------------------------------
              1     +DG1/prod1/onlinelog/group_1.265.3  
              1     +DG2/prod1/onlinelog/group_1.257.1  
              2     +DG1/prod1/onlinelog/group_2.266.3  
              2     +DG2/prod1/onlinelog/group_2.258.1   
2n. Create pfile from spfile.

Create and retain a copy of the database pfile. You'll add more RAC specific parameters to the pfile later, in the Post Installation.

SQL> connect sys/sys@prod1 as sysdba
Connected.
SQL> create pfile='/tmp/tmppfile.ora' from spfile;

File created.
2o. Add additional control file.

If an additional control file is required for redundancy, you can create it in ASM as you would on any other filesystem.

SQL> connect sys/sys@prod1 as sysdba
Connected to an idle instance.
SQL> startup mount
ORACLE instance started.
 
Total System Global Area      419430400 bytes
Fixed Size                    779416 bytes
Variable Size                 128981864 bytes
Database Buffers              289406976 bytes
Redo Buffers                  262144 bytes
Database mounted.

SQL> alter database backup controlfile to '+DG2/cf2.dbf';
 
Database altered.
 
SQL> alter system set control_files='+DG1/cf1.dbf ','+DG2/cf2.dbf' scope=spfile;
 
System altered.
 
SQL> shutdown immediate; 
ORA-01109: database not open
 
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.
 
Total System Global Area      419430400 bytes
Fixed Size                    779416 bytes
Variable Size                 128981864 bytes
Database Buffers              289406976 bytes
Redo Buffers                  262144 bytes
Database mounted.
Database opened.
SQL> select name from v$controlfile;

NAME
---------------------------------------
+DG1/cf1.dbf
+DG2/cf2.dbf
After successfully migrating all the data files over to ASM, the old data files are no longer needed and can be removed. Your single-instance database is now running on ASM!


Step 3: Install Cluster Ready Services (CRS) Software

CRS requires two files—the Oracle Cluster Registry (OCR) and the Voting Disk—on shared raw devices or Oracle Cluster File System (OCFS). These files must be accessible to all nodes in the cluster. Raw devices are used here to house both files.

3a. Create OCR and Voting Disk.

The storage size for the OCR should be at least 100MB and the storage size for the voting disk should be at least 20MB.

File
Raw Device
Disk Partition
Filename
Size (MB)
OCR /dev/raw/raw11 /dev/sde1 /u02/oradata/prod1/ocr 100
Voting Disk /dev/raw/raw12 /dev/sde2 /u02/oradata/prod1/vdisk 20
[root@salmon1]# more /etc/sysconfig/rawdevices
/dev/raw/raw11  /dev/sde1
/dev/raw/raw12  /dev/sde2
[root@salmon1]# chown oracle:dba /dev/raw/raw11
[root@salmon1]# chown oracle:dba /dev/raw/raw12
[root@salmon1]# /sbin/service rawdevices restart
Assigning devices:
           /dev/raw/raw11  -->   /dev/sde1
/dev/raw/raw11: bound to major 8, minor 65
           /dev/raw/raw12  -->   /dev/sde2
/dev/raw/raw12: bound to major 8, minor 66
done
[root@salmon1]# su - oracle
[oracle@salmon1]$ ln -s /dev/raw/raw11 /u02/oradata/prod1/ocr
[oracle@salmon1]$ ln -s /dev/raw/raw12 /u02/oradata/prod1/vdisk
3b. Install CRS software.

Before installing the CRS software, shut down the listener, database, and ASM instance. Mount the CRS CD or download the software from OTN. The OUI should be launched on only the first node. During installation, the installer automatically copies the software to the second node.

[oracle@salmon1]$ export ORACLE_BASE=/u01/app/oracle
[oracle@salmon1]$ /mnt/cdrom/runInstaller
  1. Welcome - Click on "Next."
  2. Specify File Locations:
    1. Name: OraCr10g_home1
    2. Path: /u01/app/oracle/product/10.1.0/crs_1
  3. Language Selection - English
  4. Cluster Configuration:
    1. Cluster Name: crs
    2. Public Node Name: salmon1, Private Node Name: sallocal1
    3. Public Node Name: salmon2, Private Node Name: sallocal2
  5. Private Interconnect Enforcement:
    1. Interface Name: eth0, Subnet: 192.168.0.0, Interface Type: Public
    2. Interface Name: eth1, Subnet: 10.10.10.0, Interface Type: Private
  6. Oracle Cluster Registry:
    1. Specify OCR Location: /u02/oradata/prod1/ocr
  7. Voting Disk:
    1. Enter Voting disk filename: /u02/oradata/prod1/vdisk
  8. Execute /u01/app/oracle/oraInventory/orainstRoot.sh script from another window as the root user on the first node.
  9. Execute /u01/app/oracle/oraInventory/orainstRoot.sh script from another window as the root user on the second node.
  10. Click on "Continue" after the orainstRoot.sh has been run on both nodes.
  11. Summary - Click on "Install"
  12. Execute /u01/app/oracle/product/10.1.0/crs_1/root.sh script from another window as the root user on the first node. Do not run the next step until this step completes.
  13. Execute /u01/app/oracle/product/10.1.0/crs_1/root.sh script from another window as the root user on the second node.
  14. Click on "OK" after the root.sh has been run on both nodes.
  15. End of Installation - Click on "Exit."
[oracle@salmon1]$ /u01/app/oracle/product/10.1.0/crs_1/bin/olsnodes -n
salmon1 1
salmon2 2
[oracle@salmon1]$ ps -ef | egrep "css|crs|evm"
                                

Step 4: Install Oracle RAC Software

4a. Edit the oracle user environment file.

On node 1, set ORACLE_SID=prod1a.

On node 2, set ORACLE_SID=prod1b.

[oracle@salmon1]$ more .bash_profile
# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

export PATH=$PATH:$HOME/bin
export ORACLE_SID=prod1a
export ORACLE_BASE=/u01/app/oracle
export ORACLE_HOME=$ORACLE_BASE/product/10.1.0/db_1
export ORA_CRS_HOME=$ORACLE_BASE/product/10.1.0/crs_1 
export LD_LIBRARY_PATH=$ORACLE_HOME/lib
export PATH=$ORACLE_HOME/bin:$PATH
umask 022
4b. Install RAC software.

Mount the Oracle Database 10g Enterprise Edition CD or download the software from OTN. Launch the OUI on only the first node. During installation, the installer automatically copies the software to the second node.

[oracle@salmon1]$ . ~/.bash_profile
[oracle@salmon1]$ /mnt/cdrom/runInstaller
  1. Welcome - Click on "Next."
  2. Specify File Locations:
    1. Name: OraDB10g_home1
    2. Path: /u01/app/oracle/product/10.1.0/db_1
  3. Specify Hardware Cluster Installation Mode:
    1. Select "Cluster Installation"
    2. Click on "Select All"
  4. Select Installation Type:
    1. Select "Enterprise Edition"
  5. Product-specific Prerequisite Checks:
    1. Verify that all checks are successful before proceeding. Ignore the openmotif-2.1.30-11 warning.
  6. Select Database Configuration:
    1. Select "Do not create a starter database"
  7. Summary - Click on "Install"
  8. Execute /u01/app/oracle/product/10.1.0/db_1/root.sh script from another window as the root user on the first node. Do not run root.sh on the second node until the VIP configuration completes.
  9. VIPCA Welcome - Click on "Next"
  10. VIP Configuration Assistance, 1 of 2: Network Interfaces:
    1. Select "eth0"
  11. VIP Configuration Assistance, 2 of 2: Virtual IPs for cluster nodes:
    1. Node Name: salmon1
    2. IP Alias Name: salmon1-vip
    3. IP address: 192.168.0.186
    4. Subnet Mask: 255.255.255.0
    5. Node Name: salmon2
    6. IP Alias Name: salmon2-vip
    7. IP address: 192.168.0.187
    8. Subnet Mask: 255.255.255.0
  12. Summary- Click on "Finish"
  13. Configuration Assistant Progress Dialog - Click on "OK"
  14. Configuration Results - Click on "Exit"
  15. Execute /u01/app/oracle/product/10.1.0/db_1/root.sh script from another window as the root user on the second node.
  16. Click on "OK" after the root.sh has run on both nodes.
  17. End of Installation - Click on "Exit"
4c. Configure Oracle Listener.

The Network Configuration Assistant (NETCA) should only be launched and configured on one node. At the end of the configuration process, the NETCA starts up the Oracle listener on both nodes.

[oracle@salmon1]$ netca 
  1. Oracle Net Configuration Assistant: Real Application Clusters, Configuration:
    1. Select "Cluster configuration"
  2. Oracle Net Configuration Assistant: TOPSNodes:
    1. Click "Select all nodes"
  3. Oracle Net Configuration Assistant: Welcome:
    1. Select "Listener configuration"
  4. Oracle Net Configuration Assistant: Listener Configuration, Listener:
    1. Select "Add"
  5. Oracle Net Configuration Assistant: Listener Configuration, Listener Name:
    1. Listener Name: LISTENER
  6. Oracle Net Configuration Assistant: Listener Configuration, Select Protocols
    1. Selected Protocols: TCP
  7. Oracle Net Configuration Assistant: Listener Configuration, TCP/IP Protocol:
    1. Select "Use the standard port number of 1521"
  8. Oracle Net Configuration Assistant: Listener Configuration, More Listeners?
    1. Select "No"
  9. Oracle Net Configuration Assistant: Listener Configuration Done:
    1. Click on "Next"
  10. Oracle Net Configuration Assistant: Welcome
    1. Select "Naming Methods configuration"
    2. Click on "Next"
  11. Oracle Net Configuration Assistant: Naming Methods Configuration, Select Naming:
    1. Select "Local Naming"
  12. Oracle Net Configuration Assistant: Naming Methods Configuration Done:
    1. Click on "Next"
  13. Oracle Net Configuration Assistant: Welcome
    1. Click on "Finish"
4d. Verify status of services.

On node 1:

[oracle@salmon1]$ srvctl status nodeapps -n salmon1
VIP is running on node: salmon1
GSD is running on node: salmon1
Listener is running on node: salmon1
ONS daemon is running on node: salmon1
On node 2:
[oracle@salmon2]$ srvctl status nodeapps -n salmon2
VIP is running on node: salmon2
GSD is running on node: salmon2
Listener is running on node: salmon2
ONS daemon is running on node: salmon2
4e. listener.ora file

On node 1:

[oracle@salmon1]$ more $ORACLE_HOME/network/admin/listener.ora

LISTENER_SALMON1 =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS_LIST =
          (ADDRESS = (PROTOCOL = TCP)(HOST = salmon1-vip)(PORT = 1521))
      )
      (ADDRESS_LIST =
          (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.184)(PORT = 1521))
      )
    )
  )

SID_LIST_LISTENER_SALMON1 =
  (SID_LIST =
      (SID_DESC =
          (SID_NAME = PLSExtProc)
          (ORACLE_HOME = /u01/app/oracle/product/10.1.0/db_1)
          (PROGRAM = extproc)
      )
  )
On node 2:
[oracle@salmon2]$ more $ORACLE_HOME/network/admin/listener.ora

LISTENER_SALMON2 =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS_LIST =
          (ADDRESS = (PROTOCOL = TCP)(HOST = salmon2-vip)(PORT = 1521))
      )
      (ADDRESS_LIST =
          (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.185)(PORT = 1521))
      )
    )
  )

SID_LIST_LISTENER_SALMON2 =
  (SID_LIST =
      (SID_DESC =
          (SID_NAME = PLSExtProc)
          (ORACLE_HOME = /u01/app/oracle/product/10.1.0/db_1)
          (PROGRAM = extproc)
      )
  )
4f. tnsnames.ora file

On both nodes:

[oracle@salmon1]$ more $ORACLE_HOME/network/admin/tnsnames.ora
LISTENERS_PROD1 =
  (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = salmon1-vip)(PORT = 1521))
      (ADDRESS = (PROTOCOL = TCP)(HOST = salmon2-vip)(PORT = 1521))
  )

PROD1 =
  (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = salmon1-vip)(PORT = 1521))
      (ADDRESS = (PROTOCOL = TCP)(HOST = salmon2-vip)(PORT = 1521))
      (LOAD_BALANCE = yes)
      (CONNECT_DATA =
          (SERVICE_NAME = PROD1)
          (FAILOVER_MODE =
              (TYPE = SELECT)
              (METHOD = BASIC)
              (RETRIES = 200)
              (DELAY = 5)
          )
      )
  )
PROD1A =
(DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = salmon1-vip)(PORT = 1521))
    (CONNECT_DATA =
        (SERVER = DEDICATED)
        (SERVICE_NAME = PROD1)
        (INSTANCE_NAME = PROD1A)
    )
)

PROD1B =
  (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = salmon2-vip)(PORT = 1521))
      (CONNECT_DATA =
          (SERVER = DEDICATED)
          (SERVICE_NAME = PROD1)
          (INSTANCE_NAME = PROD1B)
      )
  )
                                

Step 5: Post Installation

5a. Relocate the ASM instance files on the first node.

Copy the ASM instance password file and spfile+ASM1A.ora to the new Oracle Home.

[oracle@salmon1]$ cp /u01/app/oracle/product/10.1.0/dbs/orapw+ASM1A 
/u01/app/oracle/product/10.1.0/db_1/dbs
[oracle@salmon1]$ cp /u01/app/oracle/product/10.1.0/dbs/spfile+ASM1A.ora 
/u01/app/oracle/product/10.1.0/db_1/dbs 
5b. Create init.ora for the second ASM instance.

On the second node, create an init+ASM1B.ora file in $ORACLE_HOME/dbs.

asm_diskgroups='DG1', ‘DG2’, ‘RECOVERYDEST’
asm_diskstring='ORCL:VOL*'
background_dump_dest=/u01/app/oracle/admin/+ASM/bdump
core_dump_dest=/u01/app/oracle/admin/+ASM/cdump
user_dump_dest=/u01/app/oracle/admin/+ASM/udump
instance_type=asm
large_pool_size=16M
remote_login_passwordfile=exclusive
+ASM1A.instance_number=1
+ASM1B.instance_number=2
5c. Create password file for the second ASM instance.

Using the orapwd utility, create an orapw+ASM1B file in $ORACLE_HOME/dbs on the second node.

5d. Create the second ASM instance.

Create the second ASM instance on the second node.

[oracle@salmon2]$ export ORACLE_SID=+ASM1B
[oracle@salmon2]$ sqlplus / as sysdba

SQL*Plus: Release 10.1.0.3.0 - Production on Thu May 26 18:43:14 2005
 
Copyright (c) 1982, 2004, Oracle.  All rights reserved.
 
Connected to an idle instance.
 
SQL> startup
ORACLE instance started.
 
Total System Global Area  104857600 bytes
Fixed Size                777616 bytes
Variable Size             104079964 bytes
Database Buffers          0 bytes
Redo Buffers              0 bytes
ASM diskgroups mounted
SQL> create spfile from pfile;

File created.

SQL> shutdown immediate;
5e. Register the ASM instances with CRS.

For higher availability, register the ASM instances under the CRS framework. When registered, the CRS should detect any failed instances and automatically attempt to start up the instances. The CRS should also automatically start up the instances when the servers are rebooted.

On node 1:

                                 
[oracle@salmon1]$ srvctl add asm -n salmon1 -i +ASM1A -o /u01/app/oracle/product/10.1.0/db_1
[oracle@salmon1]$ srvctl start asm -n salmon1 
[oracle@salmon1]$ srvctl status asm -n salmon1 
ASM instance +ASM1A is running on node salmon1. 

                              
On node 2:
                                 
[oracle@salmon2]$ srvctl add asm -n salmon2 -i +ASM1B -o /u01/app/oracle/product/10.1.0/db_1
[oracle@salmon2]$ srvctl start asm -n salmon2 
[oracle@salmon2]$ srvctl status asm -n salmon2 
ASM instance +ASM1B is running on node salmon2.  

[oracle@salmon1]$ ps -ef | grep dbw | grep -v grep
oracle    8918     1  0   May 26 ?       00:00:01 asm_dbw0_+ASM1A
[oracle@salmon1]$ kill -9 8918
[oracle@salmon1]$ srvctl status asm –n salmon1
ASM instance +ASM1A is not running on node salmon1.
[oracle@salmon1]$ ps -ef | grep dbw | grep -v grep
[oracle@salmon1]$ srvctl status asm –n salmon1
ASM instance +ASM1A is running on node salmon1.
[oracle@salmon1]$ ps -ef | grep dbw | grep -v grep
oracle    8920     1  0   May 26 ?       00:00:01 asm_dbw0_+ASM1A

                              
5f. Create password files for both RAC instances.

Using the orapwd utility, create an orapwprod1a file in $ORACLE_HOME/dbs on the first node and an orapwprod1b file in $ORACLE_HOME/dbs on the second node.

5g. Add RAC specific parameters in pfile.

Modify the pfile saved in Step 2n. Add and modify the following parameters:

*.cluster_database_instances=2
*.cluster_database=true
*.remote_listener='LISTENERS_PROD1’
prod1a.thread=1
prod1a.instance_number=1
prod1a.undo_tablespace='UNDOTBS1'
prod1b.thread=2
prod1b.instance_number=2
prod1b.undo_tablespace='UNDOTBS2'
5h. Modify init.ora of both RAC instances.

On node 1:

[oracle@salmon1]$ more $ORACLE_HOME/dbs/initprod1a.ora
spfile='+DG1/spfileprod1.ora'
On node 2:
[oracle@salmon2]$ more $ORACLE_HOME/dbs/initprod1b.ora
spfile='+DG1/spfileprod1.ora'
5i. Migrate database spfile to ASM.
SQL> !echo $ORACLE_SID
prod1a

SQL> connect / as sysdba
Connected to an idle instance.
SQL> startup pfile=/tmp/tmppfile.ora
ORACLE instance started.

Total System Global Area     419430400 bytes
Fixed Size                   779416 bytes
Variable Size                128981864 bytes
Database Buffers             289406976 bytes
Redo Buffers                 262144 bytes
Database mounted.
Database opened.

SQL> create spfile='+DG1/spfileprod1.ora' from pfile='/tmp/tmppfile.ora';

File created.

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.
 
Total System Global Area     419430400 bytes
Fixed Size                   779416 bytes
Variable Size                128981864 bytes
Database Buffers             289406976 bytes
Redo Buffers                 262144 bytes
Database mounted.
Database opened.
SQL> show parameter spfile
 
NAME                       TYPE             VALUE
----------------------     ------------     ---------------------------
spfile                     string           +DG1/spfileprod1.ora
5j. Create RAC Data Dictionary Views.

Create the RAC data dictionary views on the first RAC instance.

SQL> !echo $ORACLE_SID
prod1a

SQL> spool /tmp/catclust.log
SQL> @$ORACLE_HOME/rdbms/admin/catclust
...
...
...
SQL> spool off
SQL> shutdown immediate;
5k. Register the RAC instances with CRS.

On node 1:

[oracle@salmon1]$ srvctl add database -d prod1 -o $ORACLE_HOME 
[oracle@salmon1]$ srvctl add instance -d prod1 -i prod1a -n salmon1
[oracle@salmon1]$ srvctl add instance -d prod1 -i prod1b -n salmon2
[oracle@salmon1]$ srvctl start instance -d prod1 -i prod1a
5l. Create redo logs for the second RAC instance.
SQL> connect sys/sys@prod1a as sysdba
Connected.
SQL> alter database add logfile thread 2 group 3 size 100M;
SQL> alter database add logfile thread 2 group 4 size 100M;
SQL> select group#, member from v$logfile;
 
         GROUP#    MEMBER
---------------    ----------------------------------------
              1    +DG1/prod1/onlinelog/group_1.265.3  
              1    +DG2/prod1/onlinelog/group_1.257.1  
              2    +DG1/prod1/onlinelog/group_2.266.3  
              2    +DG2/prod1/onlinelog/group_2.258.1   
              3    +DG1/prod1/onlinelog/group_3.268.1
              3    +DG2/prod1/onlinelog/group_3.259.1
              4    +DG1/prod1/onlinelog/group_4.269.1
              4    +DG2/prod1/onlinelog/group_4.260.1

8 rows selected.

SQL> alter database enable thread 2;

Database altered.
5m. Create undo tablespace for the second RAC instance.
SQL> create undo tablespace UNDOTBS2 datafile size 200M;

SQL> select tablespace_name, file_name from dba_data_files
     2    where tablespace_name=’UNDOTBS2’;
 
TABLESPACE               FILE_NAME                                          
---------------------    --------------------------------------
UNDOTBS2                 +DG1/prod1/datafile/undotbs2.270.1   
5n. Start up the second RAC instance.
[oracle@salmon1]$ srvctl start instance -d prod1 -i prod1b
[oracle@salmon1]$ crs_stat -t
Name                 Type            Target     State      Host        
-----------------------------------------------------------------------
ora....1a.inst       application     ONLINE     ONLINE     salmon1 
ora....1b.inst       application     ONLINE     ONLINE     salmon2
ora.prod1.db         application     ONLINE     ONLINE     salmon1
ora....M1A.asm       application     ONLINE     ONLINE     salmon1
ora....M1B.asm       application     ONLINE     ONLINE     salmon2
ora....N1.lsnr       application     ONLINE     ONLINE     salmon1
ora....on1.gsd       application     ONLINE     ONLINE     salmon1
ora....on1.ons       application     ONLINE     ONLINE     salmon1
ora....on1.vip       application     ONLINE     ONLINE     salmon1
ora....N2.lsnr       application     ONLINE     ONLINE     salmon2 
ora....on2.gsd       application     ONLINE     ONLINE     salmon2
ora....on2.ons       application     ONLINE     ONLINE     salmon2
ora....on2.vip       application     ONLINE     ONLINE     salmon2
[oracle@salmon1]$ srvctl status database -d prod1
Instance prod1a is running on node salmon1
Instance prod1b is running on node salmon2
[oracle@salmon1]$ srvctl stop database -d prod1
[oracle@salmon1]$ srvctl start database -d prod1
[oracle@salmon1]$ sqlplus system/system@prod1

SQL*Plus: Release 10.1.0.3.0 - Production on Fri May 27 05:53:21 2005
 
Copyright (c) 1982, 2004, Oracle.  All rights reserved.
 

Connected to:
Oracle Database 10g Enterprise Edition Release 10.1.0.3.0 - Production
With the Partitioning, Real Application Clusters, OLAP and Data Mining options

SQL> select instance_number instance#, instance_name, host_name, status 
     2    from gv$instance;
   
        INSTANCE#   INSTANCE_NAME     HOST_NAME                 STATUS
-----------------   ----------------- ------------------------- -----------
                1   prod1a            salmon1.dbsconsult.com    OPEN
                2   prod1b            salmon2.dbsconsult.com    OPEN
Congratulations, you have converted your single-instance database to RAC!


Step 6: Test Transparent Application Failover (TAF)

The failover mechanism in Oracle TAF enables any failed database connections to reconnect to another node within the cluster. The failover is transparent to the user. Oracle re-executes the query on the failed over instance and continues to display the remaining results to the user.

To demonstrate the failover mechanism of the TAF option, connect to two different database sessions and execute these steps:

6a. Connect the first session using the PROD1 service.

If the returned output of failover_type and failover_mode is 'NONE', verify that the PROD1 service is configured correctly in tnsnames.ora.

SQL> connect system/system@prod1 as sysdba
Connected.

SQL> select instance_number instance#, instance_name, host_name, status 
     2    from v$instance;
   
         INSTANCE#   INSTANCE_NAME   HOST_NAME                 STATUS                                         
 -----------------   --------------  ------------------------- ----------------
                 1   prod1a          salmon1.dbsconsult.com    OPEN

SQL> select failover_type, failover_method, failed_over 
     2    from v$session where username='SYSTEM';
 
FAILOVER_TYPE              FAILOVER_MODE        FAILED_OVER
-------------------------  -------------------- ----------------------
SELECT                     BASIC                NO
6b. Shut down the instance from another session.

Connect as the sys user on prod1a instance and shut down the instance.

SQL> connect sys/sys@prod1a as sysdba
Connected.

SQL> select instance_number instance#, instance_name, host_name, status 
     2    from v$instance;
   
        INSTANCE#   INSTANCE_NAME      HOST_NAME                 STATUS                                         
-----------------   ----------------   ------------------------  ----------------
                1   prod1a             salmon1.dbsconsult.com    OPEN

SQL> shutdown abort;    
ORACLE instance shut down.
6c. Verify that the session has failed over.

From the same session in Step 6a, execute the queries below to verify that the session has failed over to another instance.

SQL> select instance_number instance#, instance_name, host_name, status 
     2    from v$instance;
   
        INSTANCE#   INSTANCE_NAME      HOST_NAME                 STATUS                                         
-----------------   ----------------   ------------------------  ----------------
                2   prod1b             salmon2.dbsconsult.com    OPEN

SQL> select failover_type, failover_method, failed_over 
     2    from v$session where username='SYSTEM';
 
FAILOVER_TYPE      FAILOVER_MODE   FAILED_OVER
-----------------  --------------  ----------------------
SELECT             BASIC            YES
                                


Conclusion

With proper planning and understanding of the RAC architecture, the transition from a single-instance database to a RAC configuration is not necessarily complex. ASM and RAC compliment each other to provide higher levels of availability, scalability, and business continuity. Hopefully, this guide has provided a clear and concise method of performing the conversion.


Vincent Chan (
vkchan99@yahoo.com) is a Senior Consultant at MSD Inc. He is an Oracle Certified Master DBA with more than nine years of experience architecting and implementing Oracle solutions for various clients.